Roller bearing



FIG. 1 is a perspective view of a roller bearing showing my new design.

FIG. 2 is a front elevation view thereof. A rear elevation view, a left side elevation view and a right side elevation view are identical to the front elevation view.

FIG. 3 is a top plan view thereof.

FIG. 4 is a bottom plan view thereof.

FIG. 5 is a cross-sectional view taken along the line 5-5 in FIG. 2.

FIG. 6 is an enlarged cross-sectional view taken along the line 6-6 in FIG. 3.

FIG. 7 is an enlarged view of the portion 7 in FIG. 6; and,

FIG. 8 is a referential view showing the rollers.

The portions of the roller bearing shown in broken lines are for the purpose of showing environmental structure only and form no part of the claimed design. The dash-dot-dash lines are boundary lines and form no part of the claimed design. 

CLAIM The ornamental design for a roller bearing, as shown and described. 